A First-principles Prediction of Two-Dimensional Superconductivity in Pristine B2C Single layer

TL;DR

This paper predicts that a pristine B2C monolayer is a two-dimensional superconductor with a transition temperature of 19.2 K, based on first-principles calculations of lattice dynamics and electron-phonon interactions.

Contribution

It introduces the first theoretical prediction of a pristine 2D superconductor with a Tc above liquid helium boiling point, using first-principles methods.

Findings

B2C monolayer is predicted to be a 2D superconductor.

Electron-phonon coupling parameter is 0.92.

Estimated Tc is 19.2 K.

Abstract

Based on first-principles lattice dynamics and electron-phonon coupling calculations, B2C sheet is predicted to be a two-dimensional (2D) phonon-mediated superconductor with a relatively high transition temperature (Tc). The electron-phonon coupling parameter calculated is 0.92, and it is mainly contributed by low frequency out-of-plane phonon modes and electronic states with a {\pi} character. When the Coulomb pseudopotential is set to 0.10, the estimated temperature Tc is 19.2 K. To be best of our knowledge, B2C is the first pristine 2D superconductor with a Tc higher than the boiling point of liquid helium.